Nitro-ortho-oxy-azo colors and process of making same.



; UNITED S ATES PATENT. ora -E.

' To all whom itmay concern:

KARL ELBEL, OF BIEBRICH, GERMANY, ASSIGNOR TO THE FIRM OI KALLE & COMPANY,

'AKTIENGESELLSCHAFT, OF BIEiBRICI-I, GERMANY.

\ NITRO-ORTHO-OX Y-AZO COLORS AND PROCESS MAKING SAME.

958,912. No Drawing.

' Be-it known that I, KARL ELBEL, doctor of philosophy and chemist, subject of the King of Prussia, residing at Biebrich-on; the-Rhine, Germany, have invented certain new and useful Improvements in the Mannfacture and Production of Pure Nitro Ortho Oxy-Azo Colorin -Matters, of .Which the following is aspeci cation.

If l-diazo-Q-oxyand 2-diazo-l-oxy-- naphthalene-sulfonic acids are treated with nitrating agents the corresponding nitrodiazo-oxv compounds are formed. But

I these bodies are not pure. They contain various by products, which are easily recognizable if the so obtained nitro-diazo-oxy alphaor betacompounds are combined for instance with naphthol forming coloring matters. The combination mass contains always besides the proper dye a certain quantity of. brown or yellowish impurities which can only be removed very diflicultly impairing largely the yield. of coloring matter. 1

I have now found that coloring matters may be obtained if the crude nitro-diazo-oxy compound is dissolved in water and alkali and reprecipitated as a zinc compound-by addition of a zinc salt and, if necessary, of common salt, and, if this zinc compound, after filtering and pressing, is combined with a suitable body for in; stance alphaor betan'aphthol. The so obtained dyes, which separate on neutralizing or acidulating the reaction mass, as water soluble. -.,zinc-alkali'compounds in a very pure state, yield when dyed. on-wool in an acid bath and subsequently tregted with a bichromate, shades which ar mnch brighter than those of nitro-oxy napthaleneazo-colors obtainable in the manner hitherto known. They do not stain white cotton contained in the'woolen fabric and show a great resistance to the potting process These advantages are consequences of the employment of zinc salts in separating the nitro-diazo-oxy compound as Well as "of the application of the. n1tro-diazo-oxy zinc compounds .for the manufacture of the dyestuffs.

In order to illustrate the new process give;the following example:

\ (a.) 270 parts of the dry zinc salt of the at from 5, to 8, centigrade, into 810 parts Specification of Letters Patent.

Application filed January 4, 1910. Serial No. 536,429.

pure nitro-azo-oxy' Patented May 24, 1910.

of sulfuric acid of 66 Baum. After the introduction is completed, the mass is cooled to about 3 centigrade and, at a temperature from 3?, to 5", centigrade, 164 parts of.

mixed acid of 38.4 per cent. nitric acidare allowed 'to run, drop by drop, onto it. After four hours stirring, the nitrating mixture is poured onto 900 parts of-ice, and the acid is separated, filtered'by suction, and pressed out. p

in 1000 parts of water; at from- 13, to 20, Centigrade, and neutralized with sodium carbonate (120 parts), the solution being filtered, and the filtrate mixed, at 35.centigrade with a filtered solution 015 150 parts ofzinc-sulfate and 500 arts of water. For the purpose of precipitating the'zinc salt, 300 parts of common salt are stirred into the solution and the zinc salt is filtered off by suction, pressed and dried, at from 40 to 50, centigrade.

(1).) In a mixture of 100 parts of caustle soda lye of 40 Baum and 100 parts of water are stirred 30 parts of alpha-naphthol. After the alpha-nap solution is cooled down to '10", centigrade and 70.5 parts of the diazo-zinc salt are In.- troduced in successive portions. After the introduction .of this salt is completed, the

mass is stirred for another three uarters of an hour and the dyestutf is poure into 1000 parts of cold water. On adding about 80 parts of'hydrochloric acid, theco oring mat ter is precipitated as a zinocompound. It

-i filtered ofi by'suction, ressed-and dried.

In the foregoing examp e the diazo-naphthol-sulfonie acid can be replacedby other analogous compounds and the alpha -naphthol can be replaced by otherchromogens.

Now wliat I claim is: v I

1. As a 'new'process the manufacture of -pure nitro-ortho-oxy-azo coloring matters by precipitatin from the reaction mass obtained byt e 'nitration of l-diazo-2-oxy naphthalene-sulfonic acids, by means of solub e zinc salts, pure nitro-l-diazo-2-oxynaphthalene-sulfonic acid in the form of a zincsalt, and combining such salt with a chromogen -to-form a soluble zinc salt, of the corresponding coloring matters.

2; As a new product the coloring matter obtained by dissolving the crude nitro-ldiazo 2'- oxy naphthalene sulfonic acid in water and a-lkali, recipitating a zinc compoundby means 0 -zinc-sulfate'and common The compressed cake is stirred 65 a101 has dissolved, the 80 2 v I -e5s,912

salt, combining this zinc compound with treated with a bichromate, bluish grey to alp-ha-naphthol and precipitating the dyeblack shades fast to potting, and which does stuii' as zinc-alkali compound by means of not stain white cotton in an acid dye bath.

an acid being a black powder soluble in In testimony-whereof I have signed my 5 water with violet-red color, changing on adname to this specification in the presence of 15 dition of alkali into a more bluish-yiolet, on two subscribing witnesses. addition of hydrochloric acid into brown-- KARL ELBEL.

red, soluble in sulfuric acid with bright 'Witnesses: greenish-blue color, yielding when dyed on JEAN GRUND,

- 10 Wool in an acid bath and subsequently .CARL GRUND. 

